KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q170324: CMD PCI-0646U Accessed in Compatibility Mode in OSR2

Article: Q170324
Product(s): Microsoft Windows 95.x Retail Product
Version(s): 2,2.1
Operating System(s): 
Keyword(s): kbhw osr2 win95 kbHardwarekbfixlist
Last Modified: 25-MAR-2002

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows 95 OEM Service Release, versions 2, 2.1 
-------------------------------------------------------------------------------

SYMPTOMS
========

When you use an IDE controller based on the CMD PCI-0646U chip set in Windows 95
OEM Service Release 2 or 2.1 (OSR2), the controller is not recognized,
protected-mode drivers are not loaded, and the controller is accessed in
Compatibility (BIOS) mode.

CAUSE
=====

The CMD PCI-0646U chip set uses some control registers in a different manner
from earlier models of CMD controllers. The Windows PCI driver accesses these
registers in a way that causes it not to recognize this controller.

RESOLUTION
==========


STATUS
======

This problem no longer occurs in Windows 98. To resolve this problem, install
the current version of Windows. For information about the current version of
Windows, visit http://www.microsoft.com/windows.

MORE INFORMATION
================


Additional query words: 95 chipset

======================================================================
Keywords          : kbhw osr2 win95 kbHardware kbfixlist
Technology        : kbWin95search kbOPKSearch kbWin95OPKOSR2 kbWin95OPKOSR210
Version           : :2,2.1
Issue type        : kbprb

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.